This invention relates generally to the art of installing pipe networks in buildings and especially to apparatus and methods for embedding pipes and pipe couplings in floors and walls and making fire-retardant pipe networks.
Until relatively recently, pipe networks were normally extended through floors of buildings by forming holes in the floors--e.g. by using void forming devices during the "pouring" of the concrete floors, by knock-out holes, by boring such holes after the floors had been formed, etc.--and thereafter extending pipes through these holes. Normally, the holes were made to be bigger than the pipes to ensure that one could easily extend pipes through the holes. Thereafter, it was necessary for workmen to fill the spaces between the pipes and floors with cement or some other substance to meet fire codes which generally do not allow holes in floors.
There have been a number of patents and other documents published, such as German Offenlegungshrift No. 2,615,428, U.S. Pat. No. 4,453,354 to Harbeke, and U.S. Pat. No. 4,261,598 to Cornwall disclosing the concept of cementing pipe coupling joints into floors when the floors are formed (sometimes called "cast-in couplings") and thereafter mating external pipes to opposite ends of the specially embedded coupling joints.
The Harbeke and Cornwall patents suggest the use of integral flanges on the ends of pipe couplings which can be used to attach the pipe couplings to form walls with nails or screws. It has also been suggested to attach cast-in pipe couplings to forms by means of separate attachment devices which must be removed before the forms are removed. Such devices are described in U.S. Pat. Nos. 4,619,087 and 4,642,956 to Gerold Harbeke. Other suggested devices hold pipes to forms by means of nails, screws and the like which, when the forms are removed rip out of the form or the pipe, such as the above-mentioned U.S. Pat. Nos. 4,261,598 to Cornwall and 4,453,354 to Harbeke. Such devices sometimes harm the forms when they are removed or harm the pipe which must remain in the concrete. A problem with both of these pipe-attachment devices is that once the form is removed they are no longer properly attached to the form and cannot again be used to hold other pipes to the form for casting additional floors of a building without once again locating and mounting pipes on the form. It is an object of this invention to provide a separate pipe-attachment device and method which does not have to be removed from a form prior to the form being removed from the cured concrete and which does not damage either the form or the pipe upon removal of the form from the cured concrete. Further, it is an object of this invention to provide a pipe-attachment device and method which remains attached to the form when the form is removed and is thereby a part of the form so that it can again be used for attaching pipes to the form when the form is used for casting additional floors.
The present inventor has suggested that either a cup or plug attachment device could be attached to a concrete-form wall for extending away from the wall and having radially-directed surfaces for contacting either interior or exterior surface of a pipe or pipe coupling and thereby holding the pipe on the form wall by friction. When the concrete has cured and the form wall is moved downwardly to remove it from the cured concrete, the attachment device remains attached to the form wall and slides away from the pipe coupling that is embedded in the concrete, thereby leaving the attachment device as part of the form to be used for casting another floor. Although this arrangement provides vast improvements over the prior art, it still has several shortcomings. One shortcoming is that in order to provide the proper lateral support for a pipe to a concrete-form wall, the attachment device must protrude outwardly away from the form wall a minimum distance which depends on the diameter of the pipe. If the diameter of the pipe is large, the attachment device must protrude further in order to prevent the pipe from being rotated off the protrusion during the pouring of the concrete. However, some concrete forms, such as tunnel forms, cannot be moved downwardly very much when they are removed from concrete. In this regard, some types of tunnel forms can only be moved one inch downwardly before they are removed laterally from the bottom of a cast floor. Thus, it is an object of this invention, to provide an attachment device for slidably attaching a pipe coupling to a concrete-form wall which provides sufficient support for the pipe coupling during the pouring of concrete, but yet which releases the pipe coupling when the form wall is only moved a very small distance therefrom.
Another shortcoming of the previously-suggested slidable attachment device is that it only provides support at the bottom of a pipe. Thus, if the pipe is relatively thin, it can bend during the pouring of concrete. Therefore, it is an object of this invention to provide a slidable attachment device which can be used to support a pipe not only at its lower end, but along the length of the pipe.
It is a further object of this invention to provide such attachment apparatus which are inexpensive to manufacture and uncomplicated to use.